The cell wall is found only in some types of cells including plant cells, fungi, algae, bacteria, and some archaea. It is absent in animal cells. In those cells where it is present, the cell wall forms a rigid, semi-permeable outermost layer that lies just outside the cell membrane. Functions of the cell wall include: 

• Rendering mechanical strength and withstanding turgor pressure in order to prevent overexpansion 
• Regulating intercellular transport
• Storing carbohydrates for use in plant growth  
• Regulating diffusion into and out of the cell 
• Prevents loss of water from the plant cell into the environment
• Controlling the direction of cell growth. 
• Protecting the cell against pathogens using a combination of passive and active defense mechanisms